Purifying brine to be used in electrolytic processes



I Patented Oct. 9, 1928.

UNITED STATES PATENT OFFICE v JULIUS DBUCKER, F COLOGNE, GERMANY, ASSIGNYOR TO I. G. FARBENINDUSTRIE AKTIENGESELLSCHAFT, 0F FRANKFO TION 0F GERMANY.

PURIFYING BRINE TO BE USED IN ELECTROLYTIC I No Drawing. Appli The present invention relates to a process of purifying brine to be used in electrolytic cells.

It is known that-the brine to be used in electrolytic processes must possess a high dey gree 0 purity in order to avoid any disturbance of the operation. In particular the presence of magnesium and calcium salts even in small amounts exerts a disturbing effect in the continuous working of an amalwith chlorine and shows an-acid reaction..

Now I have. found that by saturating the brine with an alkali metal fluoride especially with sodium fluoride, magnesium and calcium salts are precipitated quantitatively,

the acid reaction as well as the chlorine con- 3 tent of the brine notinflriencing the comprecipitation in any way.-

pleteness of the The small amounts of sodium fluoride which enter into solution, about 1 per mille, do not prejudice the working of the cell.-

cation filed August 17, 1927, Serial No. 213,

the cell and the RT-ON-THEMAIN, GERMANY, A CORPORA- nocnssns.

693, and in Germany September 29, 1926.

The process can be worked as in continuous operation.

The followi invention 1.5 kg. of sodium fluoride are stirred into 1,000 kg. of brine, saturated with chlorine and containing 33%. of sodium chloride, 80 mg. of magnesium chloride and 180 mg. of calcium chloride per litre; the precipitate is allowed to settle and is filtered. In the filtrate the MgCl acontenthas fallen to below 10 mg. of Mg(OI-I) per litre, and the CaCl -content to below 12 'mg. of Ca (OH) per litre..

Having now particularly described and ascertained the nature of. my said invention and in what manner the same is to be performed, I declare that what I claim is:

1. The process of purifying brine to be used in electrolytic processes from magnesium andcalcium salts which consists in sat urating the brine with an alkali metal'fluoride, and separating the precipitated magnesium and calcium fluorides. I I I 2. The process of purifying brine to be used in electrolytic processes from 'magnesium and calcium salts which consists in saturating the brine withsodium fluoride and separating the precipitated magnesium and calcium fluorides.

ng example will illustrate my my hand.

JULIUS DRUCKER.

In testimony whereof I have hereunto set I 

